24 © The Containment of Underground Nuclear Explosions Photo credit Defense Nuciear Agency End of Tunnel comments in its recommendation letter to the President. The Nevada Operations Office plans the individual tests with the responsible laboratory. Both Livermore and Los Alamos maintain stock- piles of holes in various areas ofthetest site.?! When a specific test is proposed, the lab will check its inventory to see if a suitable hole is available or if a new one must be drilled. Once a holeis selected, the sponsoring laboratory designs a plan to fill-in (or **stem’’) the hole to contain the radioactive material produced by the explosion. The USGS and Earth scientists from several organizations analyze the geology surround- 21Each laboratory operates its own drilling crews conunuously to maximize the economy of the drilling operation.